Container end wall construction



Dec. 26, 1967 A. J. KLEIN 3,

CONTAINER END WALL CONSTRUCTION Filed Feb. 16, 1966 ORNEY United States Patent 3,360,158 CONTAINER END WALL CONSTRUCTION Albert Joseph Klein, Arlington Heights, 111., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed Feb. 16, 1966, Ser. No. 527,970 5 Claims. (Cl. 220-66) ABSTRACT OF THE DISCLOSURE A container used to package product under high pressure is provided with a circular concave end wall which is either an ellipsoid or a surface of revolution generated by two merging arcs, which surface approximates an ellipsoid, the end wall being able to withstand pressure considerably greater than the conventional concave end wall.

This invention relates to containers adapted to withstand high pressures, and more particularly concerns an improved end wall structure for such containers.

The primary object of the present invention is to provide an improved end wall structure for pressurized con tainers capable of withstanding substantially higher pressures than those which comparable conventional end wall structures can withstand.

Another object of this invention is to provide an end wall structure for pressurized containers which aifords improved resistance to buckling without changing the weight or type of sheet metal used.

Still another object of the invention is the provision of an improved container end wall which aflords economies in pressure can production, notably in permitting the use of lighter weight plate while at the same time maintaining strength requirements.

The objects and advantages of the invention will be apparent as it becomes better understood from the follow ing description which, When read in connection with the accompanying drawings, discloses a preferred embodiment of the invention.

In the drawings:

FIG. 1 is an elevational view, partially in section, of a container embodying the present invention; and

FIG. 2 is a view of the lower end wall of the container shown in FIG. 1.

In the illustrated embodiment of the invention there is provided a pressurized container, generally designated by the numeral 10, formed of sheet metal and comprising a cylindrical body 12, a convex top wall 14, a dispensing valve 16 and a concave bottom or end wall 18. The bottom wall 18 is secured to the lower edge of the body 12 by a folded seam or bead 20 in a conventional manner. Also included within the purview of the instant invention are can constructions wherein the bottom and body are integral, ie of one piece.

Unlike conventional end walls for containers adapted to withstand high pressures, which are of hemispherical or truncated hemispherical configuration, the end wall 18 is substantially ellipsoidal in configuration, having a profile (FIG. 1) that may be a portion of an ellipse 22, the vertical or minor axis 23 of which is coincident with the axis 24 of the container. The horizontal or major axis of the ellipse is designated 36 in FIG. 1.

Tests made with pressure containers, alike with the exception of their end wall constructions, showed that end walls having the ellipsoidal structure of this invention had greatly superior strength over those of conventional structure. For instance, in tests of end walls having the same diameter D (FIG. 2) and made of 118-pound TU tin plate, the average burst pressure for the ellipsoidal ice end walls of the invention was over 44% higher than that for the conventional spherical end walls composed of the same plate.

As shown in FIG. 1, the ellipse 22 has a horizontal or major semi-axis X and a vertical or minor semi-axis -Y. The equation defining the dimensions of the maximum ellipse is:

2 a (1.4709K) (.6757K) The equation defining the dimensions of the mean or ideal ellipse is:

Satisfactory approximations of the above ellipses are obtained by forming the end wall with a central portion 31 having a relatively large or major radius of curvature R (FIG. 1) about a center 32 located on the axis 24 of the body 12 and a peripheral portion 33 having a lesser, or minor radius r of curvature. The center of curvature 34 of the peripheral portion 33 is located in an offset position with respect to the aXis of the cylindrical body 12.

The arcs described by the radii R and r are tangent or merge along a blend circle 35 which defined the central portion and has a diameter B.

Formulas for deriving the maximum and minimum length, in inches, of the radii are: for maximum length, R=3.00K and r=1.ll5K; and for miminum length, R=L6OOK and r=.400K, where K is the ratio of the end wall diameter in inches to 2.545. The mean or ideal radii are R=2.262K, and r.775K.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and scope of the invention without sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A circular concave end wall for a container adapted to withstand high internal pressure, said end wall having a conformation substantially that of a portion of an ellipsoidal shell which is a surface of revolution generated by an ellipse having its vertical axis coincident with the axis of the container, wherein the equations for the approximate dimensional limits, in inches, of the ellipse are: for minimum dimensions 2 2 (1.471K) (.675K) and for maximum dimensions where x is the horizontal distance in inches from the axis of the container to any point on the ellipse, y is the vertical distance in inches from the horizontal axis of the ellipse to any point on the ellipse, and K is the ratio of end wall diameter in inches to 2.545.

3 2. The end wall defined in claim 1, wherein the ideal dimensions of the ellipse, in inches, are obtained from the formula:

3. A circular concaveend wall for a container adapted to withstand high internal pressures, said end wall having a conformation substantially that of a surface of revolution generated by two merging arcs, a central arc struck by a major radius, and an outer arc struck by a minor radius, wherein the maximum and minimum dimensional limits, in inches, of the major radius R and the minor radius r are derived, respectively, from the following formulas:

, R=3.00K; r=1.ll5K and,

R=l.60OK; r=.400K where cireular end Wall diameter in inches 4. The end wall defined in claim 3 wherein the ideal major radius R and the ideal minor radius r are derived from the following formulas:

4 R=2.62K and r=.775K where the diameter of the circular end Wall in inches K 5 2.540

5. The end wall defined in claim 4 wherein the arcs struck by the major and minor radii are tangent at a blend circle having a diameter, in inches, about 2.093K, 10 the center of said blend circle and the center of said end wall being coincident, where end Wall diameter in inches 15 2.545

References Cited UNITED STATES PATENTS 20 943,686 12/1904 Kruse 220-66 2,244,341 6/1941 Maclean 220-66 THERON E. CONDON, Primary Examiner.

JAMES B. MARBERT, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 v 360 1 Dated 12/26/67 Inventor(5) ALBERT J. KLEIN It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

At Column 2, Lines 8 and 9, the equation should appear as follows:

X2 V I X2 1 (1.613710 1 .56969K) In Claim 1, at Line 65, the equation should appear as follows:

X l (l.6l4K) 1.57010 In Claim 4, at Column 4, Line 1, "R=2.62K" should read -R=2.262K.

This certificate supersedes Certificate of Correction issued October 8, 1974.

Signed and sealed this 15th day of April 1975.

(L IA, kttest C. ILARSZTAtL DAT? RUTH C. 12133? Cot'missioner of Patents .Lttesting Officer and Trademarks FORM PO-IOSO (IO-69) USCOMMJJC 603764569 us sovzmmun nmmue OFFICE: mo o-su-su. 

1. A CIRCULAR CONCAVE END WALL FOR A CONTAINER ADAPTED TO WITHSTAND HIGH INTERNAL PRESSURE, SAID END WALL HAVING A CONFORMATION SUBSTANTIALLY THAT OF A PORTION OF AN ELLIPSOIDAL SHELL WHICH IS A SURFACE OF REVOLUTION GENERATED BY AN ELLIPSE HAVING ITS VERTICAL AXIS COINCIDENT WITH THE AXIS OF THE CONTAINER, WHEREIN THE EQUATIONS FOR THE APPROXIMATE DIMENSIONAL LIMITS, IN INCHES, OF THE ELLIPSE ARE: FOR MIMIMUM DIMENSIONS 